In the United States

United States

The United States of America is a federal constitutional republic comprising fifty states and a federal district...

, road signs are, for the most part, standardized by federal regulations, most notably in the Manual on Uniform Traffic Control Devices

Manual on Uniform Traffic Control Devices

The Manual on Uniform Traffic Control Devices is a document issued by the Federal Highway Administration of the United States Department of Transportation to specify the standards by which traffic signs, road surface markings, and signals are designed, installed, and used...

 (MUTCD) and its companion volume the Standard Highway Signs (SHS).

Twenty-three states along with the District of Columbia and Puerto Rico

Puerto Rico

Puerto Rico , officially the Commonwealth of Puerto Rico , is an unincorporated territory of the United States, located in the northeastern Caribbean, east of the Dominican Republic and west of both the United States Virgin Islands and the British Virgin Islands.Puerto Rico comprises an...

 use the manual without any alterations, 20 states have adopted it in conjunction with a supplemental volume, and 7 states have a state version in substantial conformance to the MUTCD. There are also localized versions that are used in large cities such as New York City

New York City

New York is the most populous city in the United States and the center of the New York Metropolitan Area, one of the most populous metropolitan areas in the world. New York exerts a significant impact upon global commerce, finance, media, art, fashion, research, technology, education, and...

 which use a naming system compatible with the MUTCD and/or state supplement. The MUTCD and SHS establish seven general categories of signs for road and highway use (all signs from national MUTCD, unless noted):

Regulatory

Regulatory signs give instructions to motorists, pedestrians and cyclists. Signs such as stop, no parking, no turns and yield are considered regulatory signs. Some have special shapes, such as the octagon for the stop sign and the X shape for railroad crossings. Some signs can be localized, such as no parking and some are only found in state and local jurisdictions as they are based on state or local laws, such as New York City's "Don't Block the Box" signs. These signs are in the R series of signs in the MUTCD and typically in the R series in most state supplements or state MUTCDs.

R1 Series: Stop and Yield

The MUTCD's R1 series of signs is for stop and yield signs. As all situations are not covered, several states have their own standards in addition to the MUTCD.

R2 Series: Speed Limit

The MUTCD's R2 series of signs is for speed limit signs. Some state supplements and state MUTCDs place various speed limit signs in other series. As all situations are not covered, several states have their own standards in addition to the MUTCD.

R3 Series: Lane Usage and Turns

The MUTCD's R3 series of signs is for lane usage and turn signs. As all situations are not covered, several states have their own standards in addition to the MUTCD.

R4 Series: Regulation of Movement

The MUTCD's R4 series of signs is for the regulation of movement signs. As all situations are not covered, several states have their own standards in addition to the MUTCD.

R5 Series: Exclusionary

The MUTCD's R5 series of signs is for exclusionary signs. As all situations are not covered, several states have their own standards in addition to the MUTCD. The most common of these signs is the do not enter sign.

R6 Series: One Way and Divided Highway

The MUTCD's R6 series of signs is for one way and divided highway signs. As all situations are not covered, several states have their own standards in addition to the MUTCD. The most common of these signs is the one way sign.

R7 Series: Parking

The MUTCD allows for three types of parking signs, permissive, no parking, and no standing. However, in most states, there is an additional more restrictive one, no stopping. These signs are found in the R7 series of signs in the MUTCD. As all situations are not covered, several states and local governments have their own standards in addition to the MUTCD.

Permissive Parking

These types of signs allow for parking for either an unlimited or varied amount of time. These types are often used in conjunction with parking meter

Parking meter

A parking meter is a device used to collect money in exchange for the right to park a vehicle in a particular place for a limited amount of time. Parking meters can be used by municipalities as a tool for enforcing their integrated on-street parking policy, usually related to their traffic and...

s and parking permits. These signs are specified by the MUTCD to be green on white. Local variations do occur with additional information and slightly different designs.

No Parking

No parking signs indicate that loading or unloading there while temporarily stopped is permitted, but parking is not. Some no parking signs display time restrictions, while others are permanent restrictions. There are also temporary versions of the signs, often of similar design to the permanent ones. These signs are specified by the MUTCD to be red on white, although local variations do occur.

No Standing

No standing signs indicate that stopping temporarily to load or unload passengers is allowed, while parking is not allowed. As with no parking signs, some restrictions displayed on the signs are permanent and some are time based. The signs are also specified by the MUTCD to be red on white, but local variations exist.

No Stopping

No stopping signs indicate that stopping is only allowed in order to obey a traffic sign, signal, traffic agent, police officer, or to avoid conflicts with other vehicles. These are the most restrictive of the parking signs. They are typically red on white.

R8 Series: Parking and Emergency Restrictions

The MUTCD's R8 series of signs is for parking restriction and emergency restriction signs. As all situations are not covered, several states have their own standards in addition to the MUTCD.

R9 Series: Bicycles and Pedestrians

The MUTCD's R9 series of signs is for bicycle and pedestrian signs. As all situations are not covered, several states have their own standards in addition to the MUTCD.

R10 Series: Traffic Signal

The MUTCD's R10 series of signs is for traffic signal related signs. As all situations are not covered, several states have their own standards in addition to the MUTCD.

R11 Series: Road Closed

The MUTCD's R11 series of signs is for road closure related signs. As all situations are not covered, several states have their own standards in addition to the MUTCD.

R12 Series: Weight Limits

The MUTCD's R12 series of signs is for weight limit related signs. As all situations are not covered, several states have their own standards in addition to the MUTCD.

R13 Series: Weight Stations

The MUTCD's R13 ,m.,;m.series of signs is for weight station related signs. As all situations are not covered, several states have their own standards in addition to the MUTCD.

R14 Series: Truck Routes

The MUTCD's R14 series of signs is for truck route related signs. As all situations are not covered, several states have their own standards in addition to the MUTCD.

R15 Series: Rail and Light Rail

The MUTCD's R15 series of signs is for rail and light rail related signs. As all situations are not covered, several states have their own standards in addition to the MUTCD.

R16 Series: Seat Belts

The MUTCD's R16 series of signs is for seat belt related signs. As all situations are not covered, several states have their own standards in addition to the MUTCD.

Other Local and State Series

The MUTCD does not cover all situations, so states and local governments have developed their own regulatory signs. In these, the sign categories are assigned series either using the MUTCD style, but higher than 16 (as done in Texas), or use a unique series nomenclature system (as done in California).

Schools

The S series of signs is specially designated by the MUTCD for use around schools. Some states have additional school warning related signs in the S series as well as in the W series of warning signs and/or the R series of regulatory signs of the state supplement or state MUTCD.

Warning

Warning signs are found in the W series of the national MUTCD. They highlight existing conditions, such as a curve, school, dead end street, or traffic signal. They can also warn possible danger such as bumps, bicycles, low flying aircraft or emergency vehicles. These signs are either yellow or fluorescent yellow in color and with the exception of a few signs are usually diamond shaped and sometimes have square or rectangular smaller signs or plaques associated with them. Most W series signs can also be found in with orange backgrounds, for temporary use in situations such as construction zones. Some of the temporary use signs are only for use in temporary situations.

W1 Series: Curves and Turns

The MUTCD's W1 series of signs is for warning signs relating to curves and turns. As all situations are not covered, several states have their own standards in addition to the MUTCD.

W2 Series: Intersections

The MUTCD's W2 series of signs is for warning signs relating to intersections including traffic circles. As all situations are not covered, several states have their own standards in addition to the MUTCD.

W3 Series: Advance Traffic Control

The MUTCD's W3 series of signs is for warning signs relating to advance traffic controls such as speed limits and signals. As all situations are not covered, several states have their own standards in addition to the MUTCD. The MUTCD provides options for graphic and text signs.

W4 Series: Lanes and Merges

The MUTCD's W4 series of signs is for warning signs relating to advance traffic controls such as speed limits and signals. As all situations are not covered, several states have their own standards in addition to the MUTCD.

W5 Series: Road Width Restrictions

The MUTCD's W5 series of signs is for warning signs relating to road width restrictons. As all situations are not covered, several states have their own standards in addition to the MUTCD. The MUTCD provides options for graphic and text signs.

W6 Series: Divided Highways

The MUTCD's W6 series of signs is for warning signs relating to divided highways. As all situations are not covered, several states have their own standards in addition to the MUTCD. The MUTCD provides options for graphic and text signs.

W7 Series: Hills and Grades

The MUTCD provides several signs in the W7 series dealing with hills and grades. Several states have additional signs for other types of situations not covered by the MUTCD.

W8 Series: Pavement and Roadway Conditions

The MUTCD's W8 series of signs is for warning signs relating to pavement and roadway conditions. As all situations are not covered, several states have their own standards in addition to the MUTCD.

W9 Series: Lane Transitions

The MUTCD's W9 series of signs is for warning signs relating to lane transitions. As all situations are not covered, several states have their own standards in addition to the MUTCD.

W10 Series: Rail and Light Rail

The MUTCD's W10 series of signs is for warning signs relating to rail and light rail. As all situations are not covered, several states have their own standards in addition to the MUTCD.

W11 Series: Advance Warnings and Crossings

The MUTCD's W11 series of signs is for warning signs relating to advance warnings and crossings. As all situations are not covered, several states have their own standards in addition to the MUTCD.

Emergency Vehicles

The MUTCD only provides for a warning of fire stations in the W11 series. Most states have their own signs for other emergency vehicle types which may enter the road.

Children

The MUTCD specifies no children related signs in the W11 series. Several states, counties and municipalities have signs for situations as children at play as well as children with various medical conditions. Some of these signs vary from state to state as there is no federal standard.

Bicycles

The MUTCD provides several signs in the W11 series warning of bicycles and for signing bicycle facilities. Several states and localities have their own specific bicycle related signs as well.

Vehicles

The MUTCD provides several signs in the W11 series dealing with vehicles. Several states have additional signs for other types of vehicles and situations regarding vehicles not covered by the MUTCD.

Pedestrians, Transit, and Aviation

The MUTCD provides several signs in the W11 series dealing with pedestrians, transit, and aviation. Several states have additional signs for other types of vehicles and situations regarding vehicles not covered by the MUTCD.

Animals

The MUTCD provides several signs in the W11 series dealing with animals. Several states have additional signs for other types of animals not covered by the MUTCD.

Driveways and Entrances

The MUTCD does not provide signs in the W11 series dealing with driveways and entrances. Many states have their own sign standards dealing with these situations that they place in their own W11 series.

W12 Series: Low Clearances

The MUTCD's W12 series of signs is for warning signs relating to low clearances. As all situations are not covered, several states have their own standards in addition to the MUTCD.

W13 Series: Advisory Speeds

The MUTCD's W13 series of signs is for warning signs relating to advisory speeds. As all situations are not covered, several states have their own standards in addition to the MUTCD.

W14 Series: Dead End Streets and No Passing Zones

The MUTCD's W14 series of signs is for warning signs relating to dead end streets and no passing zones. As all situations are not covered, several states and local governments have additional signs for other types of situations not covered by the MUTCD.

W15 Series: Playgrounds

The MUTCD's W15 series of signs is for warning signs relating to playgrounds. As all situations are not covered, several states have their own standards in addition to the MUTCD.

W16 Series: Supplemental Plaques

The MUTCD's W16 series of signs is for supplemental plaques for warning signs. As all situations are not covered, several states have their own standards in addition to the MUTCD.

W17 Series: Speed Humps

The MUTCD's W17 series of signs is for warning signs relating to speed humps. As all situations are not covered, several states have their own standards in addition to the MUTCD.

W18 Series: No Traffic Signs

The MUTCD's W18 series of signs is for warning signs relating to the lack of traffic signs. As all situations are not covered, several states have their own standards in addition to the MUTCD.

W20 Series: Work Zones

The MUTCD's W20 series of signs is for warning signs relating to work zones. These signs are typically orange background ones used for temporary situations. As all situations are not covered, several states have their own standards in addition to the MUTCD.

W22 Series: Blasting Zones

The MUTCD's W22 series of signs is for warning signs relating to blasting zones. These signs are typically orange background ones used for temporary situations. As all situations are not covered, several states have their own standards in addition to the MUTCD.

W23 Series: Slow Traffic

The MUTCD's W23 series of signs is for warning signs relating to slow traffic. These signs are typically orange background ones used for temporary situations. As all situations are not covered, several states have their own standards in addition to the MUTCD.

W24 Series: Double Reverse Curves

The MUTCD's W24 series of signs is for warning signs relating to Double Reverse Curves. These signs are typically orange background ones used for temporary situations. As all situations are not covered, several states have their own standards in addition to the MUTCD.

W25 Series: Oncoming Traffic Has Extended Green

The MUTCD's W25 series of signs is for warning signs oncoming traffic having an extended green signal at a traffic light. As all situations are not covered, several states have their own standards in addition to the MUTCD.

Miscellaneous

The MUTCD does not provide signs dealing with some other road and highway situations. Many states have their own sign standards dealing with these situations.

Guide

Guide signs include highway route markers (shields), street signs, mile markers, and exit signs.
Note: State markers are illustrative examples; all states may select their own marker shapes or use the default circle. See Numbered highways in the United States#State highways and other similar systems.

For more information about highway shields by Kendrick and AARoads Shield Gallery.

Non Compliant to MUTCD Signs

There are many signs that are non-compliant to MUTCD and/or state MUTCD standards seen in use on public and semi-public roads.